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Short Citation:
OCM Partners, 2023: 2016 USGS Lidar DEM: Maine QL2, https://www.fisheries.noaa.gov/inport/item/49434.

Item Identification

Title: 2016 USGS Lidar DEM: Maine QL2
Short Name: me2016_usgs_me_ql2_dem_m6267_metadata
Status: Completed
Publication Date: 2017-06-14
Abstract:

Product: These are Digital Elevation Model (DEM) data for Franklin, Oxford, Piscataquis, and Somerset Counties, Maine as part of the required deliverables for the 2016 Maine Lidar project. Class 2 (ground) lidar points in conjunction with the hydro breaklines were used to create a 1 meter hydro-flattened raster DEM.

Geographic Extent: Four partial counties in western Maine, covering approximately 5,034 total square miles

Dataset Description: Maine 2016 QL2 Lidar project called for the planning, acquisition, processing, and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.7 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.2. The data was developed based on a horizontal projection/datum of NAD83 (2011) UTM Zone 19, meters and vertical datum of NAVD1988 (Geoid 12B), meters. Lidar data was delivered as flightline-extent unclassified LAS swaths, as processed Classified LAS 1.4 files formatted to 6,115 individual 1,500 meter x 1,500 meter tiles, as tiled intensity imagery, and as tiled bare earth DEMs; all tiled to the same 1,500 meter x 1,500 schema. Continuous breaklines were produced in Esri file geodatabase format. Continuous contours with an interval of 1 foot were created in Esri file geodatabase format.

Ground Conditions: Lidar was collected in spring of 2016, while no snow was on the ground and rivers were at or below normal levels. In order to post process the lidar data to meet task order specifications and meet ASPRS vertical accuracy guidelines, Quantum Spatial, Inc. utilized a total of 101 ground control points that were used to calibrate the lidar to known ground locations established throughout the Maine project area. An additional 205 independent accuracy checkpoints, 118 in Bare Earth and Urban landcovers (118 NVA points), 87 in Forested, Brushland/Trees, and Tall Weeds/Crops categories (87 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data. In addition to the bare earth DEMs, the topobathy lidar point data are also available. These data are available for custom download here: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=6264 Breaklines created from the lidar area also available for download in either gdb or gpkg format at: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/6264/breaklines. The DEM and breakline products have not been reviewed by the NOAA Office for Coastal Management (OCM) and any conclusions drawn from the analysis of this information are not the responsibility of NOAA, OCM or its partners.

Purpose:

To acquire detailed surface elevation data for use in conservation planning, design, research, floodplain mapping, dam safety assessments and elevation modeling, etc. Classified LAS files are used to show the manually reviewed bare earth surface. This allows the user to create intensity images, breaklines and raster DEMs. The purpose of these lidar data was to produce high accuracy 3D hydro-flattened digital elevation models (DEMs) with a 1-meter cell size. These raw lidar point cloud data were used to create classified lidar LAS files, intensity images, 3D breaklines, hydro-flattened DEMs, and contours as necessary.

Notes:

12102

Supplemental Information:

The following reports are available for this data set: 1. Maine 2016 QL2 Lidar Project Report: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/6264/supplemental/me2016_usgs_me_ql2_m6264_lidar_report.pdf 2. Maine 2016 QL2 Lidar Project Report Appendices: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/6264/supplemental/me2016_usgs_me_ql2_m6264_lidar_report_app.pdf 3. Quantum Spatial FOCUS Report: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/6264/supplemental/me2016_usgs_me_ql2_m6264_lidar_focus_report.pdf

Keywords

Theme Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION > TOPOGRAPHICAL RELIEF MAPS
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > OCEANS > COASTAL PROCESSES > COASTAL ELEVATION
ISO 19115 Topic Category
elevation
UNCONTROLLED
None DEM

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > MAINE

Physical Location

Organization: Office for Coastal Management
City: Charleston
State/Province: SC

Data Set Information

Data Set Scope Code: Data Set
Maintenance Frequency: None Planned
Data Presentation Form: Raster digital data
Distribution Liability:

Any conclusions drawn from the analysis of this information are not the responsibility of Quantum Spatial, Inc., the U.S. Geological Survey (USGS), the Maine Office of GIS, NOAA, the NOAA Office for Coastal Management (OCM) or its partners.

Data Set Credit: Acknowledgement of the U.S. Geological Survey would be appreciated for products derived from these data.

Support Roles

Data Steward

CC ID: 662489
Date Effective From: 2017-06-14
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Distributor

CC ID: 662491
Date Effective From: 2017-06-14
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Metadata Contact

CC ID: 662492
Date Effective From: 2017-06-14
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Point of Contact

CC ID: 662490
Date Effective From: 2017-06-14
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Extents

Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 1150493
W° Bound: -71.04629822983
E° Bound: -69.15957708384
N° Bound: 45.95653467626
S° Bound: 44.00349372871

Extent Group 1 / Time Frame 1

CC ID: 1150492
Time Frame Type: Range
Start: 2016-04-05
End: 2016-05-21

Spatial Information

Spatial Representation

Representations Used

Grid: Yes

Access Information

Security Class: Unclassified
Data Access Procedure:

This data can be obtained on-line at the following URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=6267;

Data Access Constraints:

No restrictions apply to this data.

Data Use Constraints:

None. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of these data may no longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of its limitations. Acknowledgement of the U.S. Geological Survey would be appreciated for products derived from these data.

Distribution Information

Distribution 1

CC ID: 720880
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=6267
Distributor:
File Name: Customized Download
Description:

Create custom data files by choosing data area, product type, map projection, file format, datum, etc.

Distribution 2

CC ID: 720881
Download URL: https://coast.noaa.gov/htdata/raster2/elevation/ME_QL2_DEM_2016_6267
Distributor:
File Name: Bulk Download
Description:

Simple download of data files.

URLs

URL 1

CC ID: 720883
URL: https://coast.noaa.gov/dataviewer
URL Type:
Online Resource

URL 2

CC ID: 720884
URL: https://coast.noaa.gov/dataregistry
URL Type:
Online Resource

URL 3

CC ID: 720885
URL: https://coast.noaa.gov
URL Type:
Online Resource

URL 4

CC ID: 720886
URL: https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/6264/supplemental/me2016_usgs_me_ql2_m6264.kmz
Name: Browse Graphic
URL Type:
Browse Graphic
File Resource Format: kmz
Description:

This graphic shows the lidar footprint for the 2016 USGS Maine QL2 lidar project.

Activity Log

Activity Log 1

CC ID: 662514
Activity Date/Time: 2017-05-23
Description:

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 662513
Activity Date/Time: 2017-11-14
Description:

Converted from FGDC Content Standards for Digital Geospatial Metadata (version FGDC-STD-001-1998) using 'fgdc_to_inport_xml.pl' script. Contact Tyler Christensen (NOS) for details.

Activity Log 3

CC ID: 718365
Activity Date/Time: 2018-02-08
Description:

Partial upload of Positional Accuracy fields only.

Activity Log 4

CC ID: 720882
Activity Date/Time: 2018-02-13
Description:

Partial upload to move data access links to Distribution Info.

Data Quality

Vertical Positional Accuracy:

The project specifications require the accuracy (ACCz) of the derived DEM be calculated and reported in two ways: 1. The required NVA is: 19.6 cm at a 95% confidence level, derived according to NSSDA, i.e., based on RMSE of 10 cm in the "bare earth" and "urban" land cover classes. This is a required accuracy. The NVA was tested with 118 checkpoints located in bare earth and urban (non-vegetated) areas. 2. Vegetated Vertical Accuracy (VVA): VVA shall be reported for "forested", "brushland/trees", and "tall weeds/crops" land cover classes. The target VVA is: 29.4 cm at the 95th percentile, derived according to ASPRS Guidelines, Vertical Accuracy Reporting for Lidar Data, i.e., based on the 95th percentile error in all vegetated land cover classes combined. This is a target accuracy. The VVA was tested with 87 checkpoints located in forested, brushland/trees, and tall weeds/crops (vegetated) areas. The checkpoints were distributed throughout the project area and were surveyed using GPS techniques. See survey report for additional survey methodologies. AccuracyZ has been tested to meet 19.6 cm or better Non-Vegetated Vertical Accuracy at 95% confidence level using RMSE(z) x 1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASRPS Guidelines.; Quantitative Value: 0.113 meters, Test that produced the value: Tested 0.113 meters NVA at a 95% confidence level using RMSE(z) x 1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA). The NVA of the DEM was calculated using 118 independent checkpoints located in the Bare Earth and Urban land cover categories.; Quantitative Value: 0.253 meters, Test that produced the value: Tested 0.253 meters VVA was calculated using 87 checkpoints located in the Forested, Brushland/Trees, and Tall Weeds/Crops land cover categories at the 95th percentile, derived according to ASPRS Guidelines, Vertical Accuracy Reporting for Lidar Data. Tested against the DEM.

Completeness Report:

Datasets contain complete coverage of tiles. No points have been removed or excluded. A visual qualitative assessment was performed to ensure data completeness. There are no void areas or missing data. The raw point cloud is of good quality and data passes Non-Vegetated Vertical Accuracy specifications.

Conceptual Consistency:

Data covers the entire area specified for this project.

Lineage

Process Steps

Process Step 1

CC ID: 1150487
Description:

Raw Data and Boresight Processing: The boresight for each lift was done individually as the solution may change slightly from lift to lift. The following steps describe the Raw Data Processing and Boresight process: 1) Technicians processed the raw data to LAS format flight lines using the final GPS/IMU solution. This LAS data set was used as source data for boresight. 2) Technicians first used Quantum Spatial, Inc. proprietary and commercial software to calculate initial boresight adjustment angles based on sample areas selected in the lift. These areas cover calibration flight lines collected in the lift, cross tie and production flight lines. These areas are well distributed in the lift coverage and cover multiple terrain types that are necessary for boresight angle calculation. The technician then analyzed the results and made any necessary additional adjustment until it is acceptable for the selected areas. 3) Once the boresight angle calculation was completed for the selected areas, the adjusted settings were applied to all of the flight lines of the lift and checked for consistency. The technicians utilized commercial and proprietary software packages to analyze how well flight line overlaps match for the entire lift and adjusted as necessary until the results met the project specifications. 4) Once all lifts were completed with individual boresight adjustment, the technicians checked and corrected the vertical misalignment of all flight lines and also the matching between data and ground truth. The relative accuracy was less than or equal to 7 cm RMSEz within individual swaths and less than or equal to 10 cm RMSEz or within swath overlap (between adjacent swaths). 5) The technicians ran a final vertical accuracy check of the boresighted flight lines against the surveyed check points after the z correction to ensure the requirement of NVA = 19.6 cm 95% Confidence Level (Required Accuracy) was met.

Process Date/Time: 2016-01-01 00:00:00

Process Step 2

CC ID: 1150488
Description:

LAS Point Classification: The point classification is performed as described below. The bare earth surface is then manually reviewed to ensure correct classification on the Class 2 (Ground) points. After the bare-earth surface is finalized, it is then used to generate all hydro-breaklines through heads-up digitization. All ground (ASPRS Class 2) lidar data inside of the Lake Pond and Double Line Drain hydro-flattened breaklines were then classified to Water (ASPRS Class 9) using TerraScan macro functionality. A buffer of 1 meter was also used around each hydro-flattened feature to classify these ground (ASPRS Class 2) points to Ignored ground (ASPRS Class 10). All Lake Pond Island and Double Line Drain Island features were checked to ensure that the ground (ASPRS Class 2) points were reclassified to the correct classification after the automated classification was completed. All bridge decks were classified to Class 17. All overlap data was processed through automated functionality provided by TerraScan to classify the overlapping flight line data to approved classes by USGS. The overlap data was classified using standard LAS overlap bit. These classes were created through automated processes only and were not verified for classification accuracy. Due to software limitations within TerraScan, these classes were used to trip the withheld bit within various software packages. These processes were reviewed and accepted by USGS through numerous conference calls and pilot study areas. All data was manually reviewed and any remaining artifacts removed using functionality provided by TerraScan and TerraModeler. Global Mapper us used as a final check of the bare earth dataset. GeoCue was then used to create the deliverable industry-standard LAS files for both the All Point Cloud Data and the Bare Earth. Quantum Spatial, Inc. proprietary software was used to perform final statistical analysis of the classes in the LAS files, on a per tile level to verify final classification metrics and full LAS header information.

Process Date/Time: 2016-01-01 00:00:00

Process Step 3

CC ID: 1150489
Description:

Hydro Flattened Raster DEM Process: Class 2 (Ground) lidar points in conjunction with the hydro breaklines were used to create a 1 meter hydro-flattened raster DEM. Using automated scripting routines within ArcMap, an ERDAS Imagine .IMG file was created for each tile. Each surface is reviewed using Global Mapper to check for any surface anomalies or incorrect elevations found within the surface.

Process Date/Time: 2016-01-01 00:00:00

Process Step 4

CC ID: 1150490
Description:

The NOAA Office for Coastal Management (OCM) received the data in img format. The bare earth raster files were at a 1 m grid spacing. The data were in UTM Zone 19 coordinates and NAVD88 elevations in meters. OCM copied the raster files to database and https for Digital Coast storage and provisioning purposes.

Process Date/Time: 2017-05-16 00:00:00

Catalog Details

Catalog Item ID: 49434
GUID: gov.noaa.nmfs.inport:49434
Metadata Record Created By: Anne Ball
Metadata Record Created: 2017-11-15 15:13+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2022-08-09 17:11+0000
Metadata Record Published: 2022-03-16
Owner Org: OCMP
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2022-03-16
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2023-03-16